A new method for determining visual receptive fields of single neurons is described. Patterns are to be generated on a TV screen which is under computer control. The initially random patterns are modified cyclically according to an algorithm which uses the neural response, recorded by a microelectrode, and the memory of the preceeding pattern. The stimulus pattern producing optimal neural response should emerge automatically for both simple and complex fields. Extensive computer simulation studies indicate the feasibility of the method. Tests will be carried out, using the receptive fields of frog (rana pipiens) optic nerve fibers.